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From: Szabolcs Szakacsits <szaka@ntfs-3g.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	xfs@oss.sgi.com
Subject: Re: XFS vs Elevators (was Re: [PATCH RFC] nilfs2: continuous snapshotting file system)
Date: Thu, 21 Aug 2008 20:10:08 +0300 (MET DST)	[thread overview]
Message-ID: <Pine.LNX.4.61.0808211447060.4532@dhcppc2> (raw)
In-Reply-To: <20080821082532.GE5706@disturbed>


On Thu, 21 Aug 2008, Dave Chinner wrote:
> On Thu, Aug 21, 2008 at 04:04:18PM +1000, Dave Chinner wrote:
> > 
> > One thing I just found out - my old *laptop* is 4-5x faster than the
> > 10krpm scsi disk behind an old cciss raid controller.  I'm wondering
> > if the long delays in dispatch is caused by an interaction with CTQ
> > but I can't change it on the cciss raid controllers. Are you using
> > ctq/ncq on your machine?  

It's a laptop and has NCQ. It makes no difference if NCQ is enabled or 
disabled. The problem seems to be XFS only.

> > If so, can you reduce the depth to something less than 4 and see what 
> > difference that makes?
> 
> Just to point out - this is not a new problem - I can reproduce
> it on 2.6.24 as well as 2.6.26. Likewise, my laptop shows XFS
> being faster than ext3 on both 2.6.24 and 2.6.26. So the difference
> is something related to the disk subsystem on the server....

XFS definitely stalls somewhere: stats show virtually no CPU usage and no 
time spent waiting for IO. No file system produces similar output.

procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
 0  0      0 3146180   7848 600868    0    0     0  4128  790  549  0  2 98  0
 0  0      0 3145200   7848 601524    0    0     0  2372  766  516  0  2 98  0
 1  0      0 3144328   7848 602260    0    0     0  2924  792  542  1  2 98  0
 0  1      0 3143824   7856 602664    0    0     0  4116  732  426  0  2 53 45
 1  0      0 3143068   7856 603136    0    0     0  4676  756  534  0  3 95  1
 0  0      0 3142652   7856 603540    0    0     0  6577  756  436  0  0 100  0
 0  0      0 3141952   7856 604100    0    0     0  5840  764  498  1  3 96  0
 0  0      0 3141424   7856 604544    0    0     0  4752  761  386  0  0 99  0
 0  0      0 3140860   7856 604916    0    0     0  6477  785  495  0  1 98  0
 0  0      0 3139980   7856 605468    0    0     0  2840  743  370  1  2 97  0
 0  0      0 3138464   7856 606884    0    0     0  4902  795  421  0  4 96  0
 0  0      0 3137636   7856 607696    0    0     0  4364  739  395  0  1 99  0
 0  0      0 3136520   7856 608220    0    0     0  6160  774  566  0  2 97  0

	Szaka

-- 
NTFS-3G:  http://ntfs-3g.org

  parent reply	other threads:[~2008-08-21 17:07 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-20  2:45 [PATCH RFC] nilfs2: continuous snapshotting file system Ryusuke Konishi
2008-08-20  7:43 ` Andrew Morton
2008-08-20  8:22   ` Pekka Enberg
2008-08-20 18:47     ` Ryusuke Konishi
2008-08-20 16:13   ` Ryusuke Konishi
2008-08-20 21:25     ` Szabolcs Szakacsits
2008-08-20 21:39       ` Andrew Morton
2008-08-20 21:48         ` Szabolcs Szakacsits
2008-08-21  2:12         ` Dave Chinner
2008-08-21  2:46           ` Szabolcs Szakacsits
2008-08-21  5:15             ` XFS vs Elevators (was Re: [PATCH RFC] nilfs2: continuous snapshotting file system) Dave Chinner
2008-08-21  6:00               ` gus3
2008-08-21  6:14                 ` Dave Chinner
2008-08-21  7:00                   ` Nick Piggin
2008-08-21  8:53                     ` Dave Chinner
2008-08-21  9:33                       ` Nick Piggin
2008-08-21 17:08                         ` Dave Chinner
2008-08-22  2:29                           ` Nick Piggin
2008-08-25  1:59                             ` Dave Chinner
2008-08-25  4:32                               ` Nick Piggin
2008-08-25 12:01                               ` Jamie Lokier
2008-08-26  3:07                                 ` Dave Chinner
2008-08-26  3:50                                   ` david
2008-08-27  1:20                                     ` Dave Chinner
2008-08-27 21:54                                       ` david
2008-08-28  1:08                                         ` Dave Chinner
2008-08-21 14:52                       ` Chris Mason
2008-08-21  6:04               ` Dave Chinner
2008-08-21  8:07                 ` Aaron Carroll
2008-08-21  8:25                 ` Dave Chinner
2008-08-21 11:02                   ` Martin Steigerwald
2008-08-21 15:00                     ` Martin Steigerwald
2008-08-21 17:10                   ` Szabolcs Szakacsits [this message]
2008-08-21 17:33                     ` Szabolcs Szakacsits
2008-08-22  2:24                       ` Dave Chinner
2008-08-22  6:49                         ` Martin Steigerwald
2008-08-22 12:44                         ` Szabolcs Szakacsits
2008-08-23 12:52                           ` Szabolcs Szakacsits
2008-08-21 11:53                 ` Matthew Wilcox
2008-08-21 15:56                   ` Dave Chinner
2008-08-21 12:51       ` [PATCH RFC] nilfs2: continuous snapshotting file system Chris Mason
2008-08-26 10:16     ` Jörn Engel
2008-08-26 16:54       ` Ryusuke Konishi
2008-08-27 18:13         ` Jörn Engel
2008-08-27 18:19         ` Jörn Engel
2008-08-29  6:29           ` Ryusuke Konishi
2008-08-29  8:40             ` Arnd Bergmann
2008-08-29 10:51               ` konishi.ryusuke
2008-08-29 11:04                 ` Jörn Engel
2008-08-29 10:45             ` Jörn Engel
2008-08-29 16:37               ` Ryusuke Konishi
2008-08-29 19:16                 ` Jörn Engel
2008-09-01 12:25                   ` Ryusuke Konishi
2008-08-20  9:47 ` Andi Kleen
2008-08-21  4:57   ` Ryusuke Konishi
  -- strict thread matches above, loose matches on Subject: below --
2008-08-21 11:05 XFS vs Elevators (was Re: [PATCH RFC] nilfs2: continuous snapshotting file system) Martin Knoblauch
2008-08-21 15:59 ` Dave Chinner

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